Investigator

Takashi Mitamura

Hokkaido University Hospital

TMTakashi Mitamura
Papers(6)
Four versus six chemo…Risk factors for lymp…Combination therapy w…Assessment for the ti…The disease sites of …Patterns and predicto…
Collaborators(10)
Tatsuya KatoTianyue ZhaiYoshito KomatsuYosuke KonnoYusuke MizukamiChisa ShimadaDaisuke EndoFumi KatoHidemichi WatariHiromi Okada‐Kanno
Institutions(3)
Hokkaido UniversityKkr Sapporo Medical C…National Institutes o…

Papers

Four versus six chemotherapy cycles in endometrial carcinoma with a high risk of recurrence: a retrospective study

Abstract Objective This study compared the survival outcomes and the incidence of chemotherapy-related adverse events in endometrial cancer patients who received four and six cycles of adjuvant chemotherapy to examine the optimal number of adjuvant chemotherapy cycles. Methods A total of 112 patients with endometrial cancer with a high risk of recurrence were retrospectively enrolled; 46 patients received four cycles and 66 received six cycles of adjuvant chemotherapy. Between-group differences of overall survival, disease-free survival, hematological and non-hematological toxicities were analyzed. Baseline patient’s background differences were assessed with inverse probability of treatment weighting using propensity score. Results Overall and disease-free survivals between the two groups were not significantly different. Paclitaxel + carboplatin, every 3–4 weeks was the most frequently used chemotherapy regimen in both groups. Patients in the six-cycle chemotherapy group developed neutropenia G4 or febrile neutropenia more frequently than those in the four-cycle group; odds ratio (95% confidence interval) is 4.07 (1.51–10.96). Peripheral sensory neuropathy was the most frequently observed non-hematological toxicity; the incidence of peripheral sensory neuropathy was not significantly different between four- and six-cycle chemotherapy group, P = 0.832. The result was same in the subgroup analysis in patients who received TC regimen, P = 0.455. Conclusion This study implies a possible benefit of fewer cycles of adjuvant chemotherapy in endometrial cancer patients with a high risk of recurrence because of the lower incidence of hematological toxicities without impairing survival outcomes.

Risk factors for lymph node metastasis of ovarian, fallopian tube and primary peritoneal cancer in hereditary breast and ovarian cancer syndrome

Abstract Background To establish an individualized surgical strategy for lymphadenectomy in ovarian cancer patients with the germline BRCA1 and BRCA2 pathogenic variants (BRCA1+ and BRCA2+), we investigated the clinicopathological characteristics that are involved in the increased risk of lymph node metastasis. Methods We retrospectively reviewed the data of Japanese women registered in the database of the Japanese Hereditary Breast and Ovarian Cancer Consortium, who underwent BRCA1 and BRCA2 genetic testing. Results We evaluated the predictors of lymph node metastasis in all patients with the information of age at the diagnosis, disease site, histological subtype, 2014 FIGO stage, personal breast cancer history and family history; 233, 153 and 32 patients in the BRCA− (no pathogenic variant), BRCA1+ and BRCA2+ groups, respectively. The prevalence of lymph node metastasis was not markedly different between BRCA− (20.0%), BRCA1+ (18.4%) and BRCA2+ (26.2%). Multivariate analysis revealed an absence of a family history of ovarian cancer as an independent predictor for an increased risk of lymph node metastasis in BRCA1+, and the prevalence of lymph node metastasis was 11.7 and 42.0% in the groups with and without a family history of ovarian cancer, respectively. This subgroup without a family history of ovarian cancer did not show any correlation with a particular variant of BRCA1, including two common variants of c.188 T > A and c.2800C > T. Conclusions This study suggested that certain genetic factors related to the penetrance of hereditary breast and ovarian cancer syndrome altered the frequency of lymph node metastasis in BRCA1+ ovarian cancer, and family history may be useful to personalize the indication of lymphadenectomy.

Combination therapy with bevacizumab and a CCR2 inhibitor for human ovarian cancer: An in vivo validation study

AbstractBackgroundAnti‐angiogenic therapy with bevacizumab (BEV), an anti‐VEGF antibody, plays a critical role in the treatment of ovarian cancer. However, despite an encouraging initial response, most tumors become resistant to BEV over time, and a new strategy that enables sustainable treatment using BEV is therefore needed.MethodsTo overcome the resistance to BEV in patients with ovarian cancer, we performed a validation study of combination therapy with BEV (10 mg/kg) and the CCR2 inhibitor BMS CCR2 22 (20 mg/kg) (BEV/CCR2i) using 3 consecutive patient‐derived xenografts (PDXs) of immunodeficient mice.ResultsBEV/CCR2i demonstrated a significant effect of growth suppression in the BEV‐resistant serous PDX and BEV‐sensitive serous PDX compared with BEV (30.4% after the second cycle and 15.5% after the first cycle, respectively), and treatment cessation did not attenuate this effect. Tissue clearing and immunohistochemistry with an anti‐α‐SMA antibody suggested that BEV/CCR2i suppressed angiogenesis from the host mice more than BEV. In addition, human CD31 immunohistochemistry revealed that BEV/CCR2i decreased microvessels originating from the patients to a significantly greater degree than BEV. Regarding the BEV‐resistant clear cell PDX, the effect of BEV/CCR2i was unclear during the first five cycles, but the following two cycles of increased‐dose BEV/CCR2i (CCR2i 40 mg/kg) significantly suppressed tumor growth compared with BEV (28.3%) by inhibiting the CCR2B‐MAPK pathway.ConclusionsBEV/CCR2i showed a sustained anticancer immunity‐independent effect in human ovarian cancer that was more significant in serous carcinoma than in clear cell carcinoma.

Assessment for the timing of comprehensive genomic profiling tests in patients with advanced solid cancers

AbstractComprehensive genomic profiling (CGP) tests have been covered by public insurance in Japan for patients with advanced solid tumors who have completed or are completing standard treatments or do not have them. Therefore, genotype‐matched drug candidates are often unapproved or off‐label, and improving clinical trial access is critical, involving the appropriate timing of CGP tests. To address this issue, we analyzed the previous treatment data for 441 patients from an observational study on CGP tests discussed by the expert panel at Hokkaido University Hospital between August 2019 and May 2021. The median number of previous treatment lines was two; three or more lines accounted for 49%. Information on genotype‐matched therapies was provided to 277 (63%). Genotype‐matched clinical trials were ineligible because of an excess number of previous treatment lines or use of specific agents were found in 66 (15%) patients, with the highest proportion in breast and prostate cancers. Many patients met the exclusion criteria of one to two or more treatment lines across cancer types. In addition, previous use of specific agents was a frequent exclusion criterion for breast, prostate, colorectal, and ovarian cancers. The patients with tumor types with a low median number (two or fewer) of previous treatment lines, including most rare cancers, primary unknown cancers, and pancreatic cancers, had significantly fewer ineligible clinical trials. The earlier timing of CGP tests may improve access to genotype‐matched clinical trials, with their proportion varying by cancer type. Each relevant society needs to advocate the desirable timing of CGP testing nationwide.

Patterns and predictors of site‐specific recurrence in cervical cancer after radical hysterectomy

AbstractAimThis study examines patterns and predictors of site‐specific recurrence to explore the causes of local recurrence of cervical cancer.MethodsRadical hysterectomy was performed in 121 patients (stage IB–IIB). Nerve‐sparing was performed whenever possible. The first recurrence in local, regional, and distant areas was examined. We investigated the possibility of nerve involvement in local recurrence, focusing on paravaginal tissues containing the pelvic plexus. We provide Supporting Information on local recurrence in the paravaginal area.ResultsLocal recurrence was an independent event from regional or distant recurrence. Local recurrence was seen only in high‐risk patients, while regional and distant recurrences were not or less related to the risk category. The independent risk factors by logistic regression for local, regional, and distant recurrence were parametrial invasion, vaginal invasion, and lymph node metastasis, respectively. Local recurrence showed a comparable or more significant negative impact on survival than distant recurrence. Among seven patients with local recurrences, five had a recurrence in the paravagina. The rate of paravaginal recurrence was one in 76 early‐stage and four in 45 locally advanced diseases. Four sites of paravaginal recurrence occurred on the nerve‐sparing side and two on the non‐nerve‐sparing side. Supporting Information demonstrated histological evidence of perineural spread into the pelvic plexus and perineural invasion of the primary tumor.ConclusionsA high percentage of local recurrences are in paravaginal tissue containing the pelvic plexus. The causal association of nerve‐sparing surgery and perineural invasion with local recurrence needs to be investigated in large prospective studies.

6Papers
17Collaborators
Ovarian NeoplasmsProstatic NeoplasmsPancreatic NeoplasmsDrug Resistance, NeoplasmDisease Models, AnimalCarcinomaUterine Cervical NeoplasmsNeoplasm Recurrence, Local

Positions

Researcher

Hokkaido University Hospital